HRAS and melanoma: However, as only 10% of the melanomas contained mutations in the H-ras and N-ras genes in the Sotillo et al. study [95], these results suggest that other genes are targets of DMBA in these animals and/or that Ras is not necessarily the gene that “drives” melanoma initiation in the response to the R24C mutation, at least in response to DMBA/TPA.